Ampitude linearity must be preserved in amplitude modulated video signals, such as NTSC television signals, to offer pleasing picture quality. When NTSC television signals are amplitude modulated onto a carrier and transmitted over a power line, it is desirable to transmit the carrier at relatively high levels (i.e. signal voltages) to overcome the ambient noise level and high propagation losses due to impedance mismatching at the transmitted frequencies. These impedance mismatches can lead not only to signal power losses but also to actual voltage rises due to impedance transformation on the power line.